1. Field of the Invention
The general field of the present invention is that of portable electric hand tools, more particularly that of reciprocating portable electric hand tools and most specifically, extended reciprocating portable electric hand tools to which any one of a variety of abrasive work performing tool heads may be attached by means of a coupling.
The innovation disclosed in U.S. Pat. No. 5,833,014 entitled `Reciprocating Tool Handle` is focussed mainly upon an extended attachment to an existing electrically powered portable reciprocating saw. The saw is recognized as prior art and the handle, comprised of a longitudinal sleeve about the extension, provides a guide for the rigid longitudinal reciprocating extension frictionally suspended therefrom and driving a tool head. It is mentioned in this disclosure that the extension may be integral to such a tool or, preferably, a detachable extension. The tool head may similarly be integral to the extension or, preferably detachable therefrom, and a wide variety of tool heads are applicable.
2. General Background
The device disclosed in the above referenced United States patent comprises a sleeve that is frictionally suspended from a rigid longitudinal extension of a power tool which may be held in guidance of a tool head so extended. As an attachment to an existing power tool, particularly to a portable reciprocating power saw, the limitations inherent to the power saw utilized are thus imposed. These saws are typically characterized by a single speed and a given stroke or travel of the reciprocating member which is typically about three quarters of an inch. This arrangement is suited to a saw quite well but the reciprocating handle opens up many diverse uses which may not be best suited to the single speed and stroke found on such a portable saw.
The relatively short stroke of a reciprocating saw is considered appropriate to the action of sawing while a longer stroke would likely be problematic in tending to grab and throw the workpiece. In other words, the stroke of the saw is considered to be deliberately short in order to ensure safe operation. The blade of a conventional portable reciprocating power saw is also immediately adjacent the main body of the saw and the cutting action enabled thereby is one in which it is desirable to have close proximity to the workpiece.
This is contrasted to the other types of work addressed by the present invention where it is desired to work at a remove from the surface or material being worked in a wide variety of tasks encompassing practically any activity effectable by reciprocal motion of a tool head. With the exception of sawing, which is not considered to be an activity suited to work at a remove, a reciprocating stroke which is substantially longer than that suited to sawing is typically considered desirable. Sanding, with a platform or block, scraping of various kinds, scrubbing with a brush, wire or various types of bristle as well as with a pad, hoeing, filing, polishing, et cetera, provide examples.
Even abrading concrete flash off Jersey barriers benefits from use of a longer stroke as does the cleaning of windows with a soft pad, for instance. Scraping barnacles off the hull of a boat benefits from the more concentrated application of force exerted by the edge of a scraper as does scraping loose paint off of a surface preparatory to painting, both of which are more quickly accomplished with a longer stroke. It is hence recognized that for nearly all purposes other than sawing, a relatively long stroke is considered desirable.
It is also considered that a rigid longitudinal extension as an attachment to a conventional reciprocating portable power saw utilizes a connection between the reciprocating member of the saw and the extension which, lacking any other structure between the handle and the saw, is considered of lesser durability than that generally desired of a conventional power hand tool. Given also that powered sanding of surfaces which would otherwise be sanded manually is considered one of the more significant uses of the reciprocating handle it is further recognized that the amount of dust resulting from powered sanding presents a health hazard while air borne and upon settling, a nuisance in cleaning up.
The use of a conventional portable reciprocating saw as the driving force for an extension of the reciprocating member with one of many other types of tool heads attached thereto is thus considered, in short, to be restrictive of the potential presented by a rigid longitudinal extension frictionally suspended within a sleeve which may be grasped in guidance of any such tool head.
Statement of Need
In recognition of the limitations imposed by using a conventional portable reciprocating power saw as a motive force for a rigid longitudinal extension simply attached thereto and the various applications addressed by a reciprocating extended tool end of various types a need is recognized for an integral reciprocating tool having a frictionally suspended rigid longitudinal extension particularly adapted to meet these various applications.